Structural Unit

ABSTRACT

A structural unit, in particular a grinding wheel has a hole pattern for sucking away swarf from a machining surface. The hole pattern has at least three recesses which are arranged essentially along a first spiral line. The hole pattern also has at least three further recesses which are arranged essentially along a second spiral line which intersects the first spiral line in a region of at least one recess.

This application is a divisional application of co-pending U.S.application Ser. No. 13/746,347, filed Jan. 22, 2013, which claimspriority under 35 U.S.C. § 119 to patent application no. DE 10 2012 201329.6, filed on Jan. 31, 2012 in Germany, the disclosures of which areincorporated herein by reference in their entirety.

BACKGROUND

A structural unit, in particular a grinding wheel, having a hole patternhas already been proposed. There is already a multiplicity of grindingwheels with hole patterns, what are known as multihole grinding wheels,such as are known, for example, from patent specification EP 0 781 629B1.

SUMMARY

A structural unit, in particular a grinding wheel, is proposed, having ahole pattern, in particular for sucking away swarf from a machiningsurface, with at least three recesses which are arranged at leastessentially along a first spiral line, and with at least three furtherrecesses which are arranged at least essentially along a second spiralline which intersects the first spiral line in the region of at leastone recess. In this context, various structural units which seemexpedient to a person skilled in the art may be envisaged such as, forexample, brake disks or shower heads, but, in particular, a grindingwheel or a grinding plate are to be understood. In this case, a“grinding wheel” is to be understood, in particular, to mean a unitwhich forms the tool of a grinding machine, in particular of aneccentric grinding machine, and, during operation, is directly incontact with a workpiece for the removal of material. The unitpreferably has at least one carrier layer and at least abrasive layer.The carrier layer is preferably composed of a paper, a foil, a fabric, afiber or a combination. However, other materials which seem expedient toa person skilled in the art may also be envisaged. The abrasive layerpreferably has granulation. Especially preferably, the unit is intendedto be connected to a grinding plate via the carrier layer. In thiscontext, a “grinding plate” is to be understood, in particular, to meana unit of a grinding machine, in particular of an eccentric grinder,which is intended to receive a tool, in particular a grinding wheel. Thegrinding plate preferably has at least one main surface of extent whichserves as a reception surface for the tool. Especially preferably, thegrinding plate is driven by the grinding machine. Furthermore, in thiscontext, a “hole pattern” is to be understood, in particular, to mean anarrangement of recesses. In this context, a “recess” is to beunderstood, in particular, to mean a through hole. It is preferably around hole, but other hole shapes which seem expedient to a personskilled in the art may also be envisaged. Moreover, a “spiral line” isto be understood in this context to mean, in particular, a curve whichruns around a spiral axis. Preferably, a spacing of points of themapping with respect to the spiral axis changes strictly monotonicallyin relation to the angle. Especially preferably, mapping of the spiralline in a polar coordinate system can be differentiated at least simplycontinuously. Furthermore, “at least essentially” is to be understood inthis context to mean, in particular, that a distance from a stipulatedvalue, in particular a stipulated position, amounts, in particular, toless than 50%, preferably to less than 25% and especially preferably toless than 10% of a diameter of the recess.

An advantageous distribution of recesses can be achieved as a result ofthe configuration according to the disclosure of the structural unithaving the hole pattern.

It is proposed, furthermore, that at least a large part of the recessesis arranged along spiral lines having in each case at least threerecesses. In this context, “large part of the recesses” is to beunderstood, in particular, to mean at least more than 50%, preferably atleast more than 70% and especially preferably at least more than 90% ofthe recesses. Advantageous surface utilization can be achieved by virtueof the configuration. Furthermore, uniform distribution can be achieved.

Moreover, it is proposed that at least a large part of the recesses isarranged at intersection points of the spiral lines. Uniform surfaceutilization can thereby advantageously be achieved.

Furthermore, it is proposed that the at least two spiral lines becontradirectional to one another with respect to a spiral axis of thespiral lines. Furthermore, in this context, “contradirectional” is to beunderstood, in particular, to mean that the spiral lines run aroundtheir spiral axes in opposite directions away from the respectivestarting points or toward the respective starting points. Especiallyadvantageous distribution of the recesses can thereby be achieved.

Furthermore, it would be conceivable that the distances in each casefrom two recesses which succeed one another directly along a spiralline, in the case of at least a large part of the recesses, vary by lessthan 60%, especially preferably by less than 50%, from the maximumdistance between two successive recesses. Especially uniformdistribution of the recesses can thereby be achieved.

Moreover, it would be conceivable that the recesses which are arrangedalong the same spiral line are arranged in each case in an angular rangeof less than 360° along the respective spiral line.

It is proposed, further, that the contradirectional spiral lines differfrom one another in their number. This is to be understood, inparticular, to mean that a number of spirals which run in one directionis different from the number of spirals which are contradirectional withrespect to these spirals.

What can advantageously be achieved thereby is that an asymmetric holepattern with advantageous surface utilization and with advantageoussurface distribution is achieved.

Moreover, it is proposed that the number of codirectional spiral linesand/or the number of contradirectional spiral linescorrespond/corresponds to a number of the Fibonacci sequence. In thiscontext, a “number of the Fibonacci sequence” is to be understood, inparticular, to mean any positive number which is part of the generalFibonacci sequence (0, 1, 1, 2, 3, 5, 8, 13, 21, . . . ). The sequencecommences with the numbers 0 and 1, all further numbers being obtainedby the addition of the two preceding numbers. Preferably, this is to beunderstood, in particular, to mean a number of the Fibonacci sequencewhich is greater than or equal to 3. Especially preferably, this is tobe understood, in particular, to mean a number of the Fibonacci sequencewhich is greater than or equal to 8.

In particular, it is proposed that the number of codirectional spirallines and the number of contradirectional spiral lines correspond to twosuccessive numbers of the Fibonacci sequence. Especially preferably, theratio of the two numbers to one another corresponds at leastapproximately to the golden section. In this context, “at leastapproximately” is to be understood to mean, in particular, that adeviation from a stipulated value amounts, in particular, to less than10%, preferably to less than 5% and especially preferably to less than2%. Furthermore, in this context, the “golden section” is to beunderstood, in particular, to mean a ratio φ. The ratio φ is given by

$\varphi = {\frac{1 + \sqrt{5}}{2} \approx {1.618.}}$

What can advantageously be achieved thereby is that the recesses aredistributed uniformly on the surface and recesses can be prevented fromlying directly one behind the other in the radial direction.

It is proposed, furthermore, that the at least one spiral linecorresponds at least approximately to a Fibonacci spiral. In thiscontext, a “Fibonacci spiral” is to be understood, in particular, tomean a spiral which is composed of quarter circles. Preferably, thesequence of the radii of the quarter circles corresponds to theFibonacci sequence, and in this case the numbers of the Fibonaccisequence are to be understood to be unitless. Especially preferably, thequarter circles are placed one against the other so as always to berotated through 90° with respect to one another. An especially uniformspiral line can thereby advantageously be achieved, as a result ofwhich, in turn, advantageous surface distribution can be achieved.

Moreover, it is proposed that at least 50% of the recesses which arearranged along a spiral line have in each case a minimum spacing withrespect to a center point which differs from all the minimum spacingswith respect to the center point of recesses which are arranged alongthe two adjacent codirectional spiral lines, so that at least 50% of therecesses of one spiral line lie on radii which are related to the centerpoint and which differ from radii on which the recesses of the adjacentspiral lines lie. Preferably, at least 70% of the recesses which arearranged along a spiral line have in each case a minimum spacing withrespect to a center point which differs from all the minimum spacingswith respect to the center point of recesses which are arranged alongthe two adjacent codirectional spiral lines. Especially preferably, atleast 90% of the recesses which are arranged along a spiral line have ineach case a minimum spacing with respect to a center point which differsfrom all the minimum spacings with respect to the center point ofrecesses which are arranged along the two adjacent codirectional spirallines. In this case, a “center point” is to be understood in thiscontext to mean, in particular, a center point of a main plane of extentof the structural unit. It would be conceivable, furthermore, that atleast 50% of the recesses which are arranged along a spiral line have ineach case a minimum spacing with respect to a center point which differsfrom all the minimum spacings with respect to the center point ofrecesses which are arranged along the two adjacent codirectional spirallines and the spiral lines adjacent to the adjacent spiral lines.

The situation can thereby advantageously be prevented where at least alarge number of recesses lies in the circumferential direction directlyin the shadow, that is to say on the same radius with respect to thecenter point, of another recess, as a result of which, with a smallfraction of holes, maximum coverage in the circumferential direction canbe achieved.

BRIEF DESCRIPTION OF THE DRAWINGS

Further advantages appear from the following drawing description. Thedrawings illustrate two exemplary embodiments of the disclosure. Thedrawings and disclosure contain numerous features in combination. Aperson skilled in the art will expediently also consider the featuresindividually and combine them into appropriate further combinations.

FIG. 1 shows a structural unit according to the disclosure with a holepattern and with spiral lines in a diagrammatic illustration, and

FIG. 2 shows a system with the structural unit according to thedisclosure and with an alternative structural unit according to thedisclosure and a machining surface in a diagrammatic illustration.

DETAILED DESCRIPTION

FIG. 1 shows a structural unit 10 according to the disclosure with ahole pattern 16 for sucking away swarf from a machining surface 18. Thestructural unit 10 is formed by a grinding wheel 12. Furthermore, thestructural unit 10 has recesses 20 which are arranged essentially alonga first spiral line 22, and further recesses 24 which are arrangedessentially along a second spiral line 26 which intersects the firstspiral line 22 in the region of a recess 20, 24. The recesses 20, 24 areformed by round holes.

All the recesses 20, 24, 28 of the structural unit 10 are arranged alongspiral lines 22, 26, 30, 32 having in each case more than three recesses20, 24, 28. The recesses 20, 24, 28 of the structural unit 10 arearranged on intersection points of the spiral lines 22, 26, 30, 32. Thespiral lines 22, 26, 30, 32 have in each case a different orientation.The spiral lines 22, 26, 30, 32 have in each case an origin, not visiblein any more detail, which is arranged in each case so as to be offsetwith respect to a center point 34 of the structural unit 10. The originsof the spiral lines 22, 26, 30, 32 are arranged approximately on anelliptic ring, not visible in any more detail, the center point of whichis arranged so as to be offset with respect to the center point 34 ofthe structural unit 10.

The spiral lines 22, 26, 30, 32 are contradirectional to one anotherwith respect to a spiral axis, not visible in any more detail, of thespiral lines 22, 26, 30, 32. Some of the spiral lines 26, 32 run, incomparison with the rest of the spiral lines 22, 30, in oppositedirections around their spiral axes away from the respective origins ortoward the respective origins.

The distances from in each case two recesses 20, 24, 28 which succeedone another directly along a spiral line 22, 26, 30, 32 vary, in thecase of the recesses 20, 24, 28, by less than 50% from the maximumdistance between two successive recesses.

The recesses 20, 24, 28 which are arranged along the same spiral line22, 26, 30, 32 are arranged in each case in an angular range of lessthan 360° along the respective spiral line 22, 26, 30, 32.

The contradirectional spiral lines 22, 26, 30, 32 differ from oneanother in their number. A number of the spiral lines 22, 30 which runin each case in the same direction with respect to their specificorientation differs from a number of spiral lines 26, 32 which run in anopposite direction thereto.

The number of codirectional spiral lines 22, 30 and the number ofcontradirectional spiral lines 26, 32 corresponds to a number of theFibonacci sequence. The number of codirectional spiral lines amounts to34. The number of contradirectional spiral lines amounts to 21. Thenumbers of spiral lines 22, 26, 30, 32 correspond to successive numbersof the Fibonacci sequence. The ratio of the two numbers thus constitutesan approximation to the golden section.

The spiral lines 22, 26, 30, 32 correspond to Fibonacci spirals. Thecodirectional spiral lines 22, 30 and the contradirectional spiral lines26, 32 are arranged in each case so as to be rotated and offset withrespect to one another. The codirectional spiral lines 22, 30 arearranged in each case to be offset to one another and successive spirallines 22, 30 are in each case rotated through approximately 10.59°.Furthermore, the contradirectional spiral lines 26, 32 are arranged ineach case so as to be offset to one another and successive spiral lines26, 32 are in each case rotated through approximately 17.14°.

The recesses 20, 24, 28 which are arranged along a spiral line 22, 26,30, 32 have in each case a minimum spacing with respect to the centerpoint 34 which differ from all the minimum spacings with respect to thecenter point 34 of recesses 20, 24, 28 which are arranged along the twoadjacent codirectional spiral lines 22, 26, 30, 32. Consequently, asseen in the circumferential direction about the center point 34 of thestructural unit 10, there is no recess 20, 24, 28 of the structural unit10 which lies directly in the shadow of another recess 20, 24, 28. Aftereach recess 20, 24, 28, a blank space lies on the successive spiral line22, 26, 30, 32, as seen in the circumferential direction. Furthermore,after a large part of the recesses 20, 24, 28, a blank space lies on thetwo successive spiral lines 22, 26, 30, 32, as seen in thecircumferential direction.

FIG. 2 shows a system with the first and with a further example of theembodiment of the disclosure. The following descriptions and drawingsare restricted essentially to a description of the combination of theexemplary embodiments. The set-up, as described above, can also beapplied to the further exemplary embodiment, with the exception of thedifferent configuration, particularly with regard to an arrangement ofthe recesses. It would also be conceivable, however, that the furtherexemplary embodiment has an alternative set-up according to thedisclosure.

FIG. 2 shows a system 36 with the structural unit 10 according to thedisclosure and with a structural unit 10′ according to the disclosure.The system 36 is formed by an eccentric grinder 38. Furthermore, thestructural unit 10′ is formed by a grinding plate 14. The grinding plate14 has recesses which are arranged correspondingly to the recesses 20,24, 28 of the grinding wheel 12. The grinding plate 14 is connecteddirectly to a drive shaft, not visible in any more detail, of theeccentric grinder 38. It would basically be conceivable however, also tohave an alternative connection between the grinding plate 14 and a driveunit, not visible in any more detail, of the eccentric grinder 38. Thegrinding wheel 12 and the grinding plate 14 are positively connected viaconnection elements, not visible in any more detail. The recesses 20,24, 28 of the grinding wheel 12 preferably lie exactly on the recessesof the grinding plate 14. Basically, however, an advantageous overlap ofthe recesses 20, 24, 28 can be achieved by means of the hole pattern 16independently of an angular position of the grinding wheel 12 on thegrinding plate 14. The grinding wheel 12 has, on a side facing away fromthe grinding plate 14, a grinding surface 40 with granulation. Amachining surface 18 is arranged parallel to the grinding surface 40.

1-11. (canceled)
 12. A structural unit having a hole pattern for suckingaway swarf from a machining surface comprising: at least three firstrecesses arranged along a first spiral line, the first spiral linehaving a first origin; at least three second recesses arranged along asecond spiral line, the second spiral line having a second origin,wherein the second spiral line intersects the first spiral line in aregion of at least one recess of the at least three first recesses andthe at least three second recesses; at least three third recessesarranged along a third spiral line, the third spiral line having a thirdorigin; at least three fourth recesses arranged along a fourth spiralline, the fourth spiral line having a fourth origin; at least threefifth recesses arranged along a fifth spiral line, the fifth spiral linehaving a fifth origin; at least three sixth recesses arranged along asixth spiral line, the sixth spiral line having a sixth origin; and atleast three seventh recesses arranged along a seventh spiral line, theseventh spiral line having a seventh origin, wherein each of the firstorigin, third origin, fourth origin, fifth origin, sixth origin, andseventh origin are located on an elliptic ring, the elliptic ring havinga first center point which is offset from a second center point of thestructural unit.
 13. The structural unit according to claim 12, whereinthe at least three first recesses are arranged at intersection points ofthe first and second spiral lines.
 14. The structural unit according toclaim 12, wherein the first and second spiral lines arecontradirectional to one another.
 15. The structural unit according toclaim 14, wherein the first and second contradirectional spiral lineshave different numbers of recesses.
 16. The structural unit according toclaim 14, wherein: the first spiral line is one of a first plurality ofspiral lines; the second spiral line is one of a second plurality ofspiral lines; each of the first plurality of spiral lines iscontradirectional to each of the second plurality of spiral lines; eachof the first plurality of spiral lines is associated with a respectiveat least three first recesses; each of the second plurality of spirallines is associated with a respective at least three second recesses; afirst total number of the first plurality of spiral lines of thestructural unit corresponds to a first Fibonacci number of a Fibonaccisequence; a second total number of the second plurality of spiral linescorrespond to a second Fibonacci number of the Fibonacci sequence; andthe first Fibonacci number is adjacent to the second Fibonacci number inthe Fibonacci sequence.
 17. The structural unit according to claim 12,wherein the first spiral line corresponds at least approximately to aFibonacci spiral.
 18. The structural unit according to claim 12,wherein: each of the at least three first recesses have a minimumspacing with respect to the second center point which differ from allminimum spacings with respect to the second center point of the at leastthree third recesses and the at least three fourth recesses; and thefourth and the fifth spiral lines are each immediately adjacent to, andcodirectional with, the first spiral line.
 19. The structural unitaccording to claim 12, wherein the structural unit is a grinding wheel.20. The structural unit according to claim 12, wherein the structuralunit is a grinding plate.
 21. A system comprising: a grinding wheelincluding: at least three first recesses arranged along a first spiralline having a first origin offset from a first center point of thegrinding wheel, at least three second recesses arranged along a secondspiral line having a second origin, wherein the second spiral lineintersects the first spiral line in a region of at least one recess ofthe at least three first recesses and the at least three secondrecesses, at least three third recesses arranged along a third spiralline, the third spiral line having a third origin, at least three fourthrecesses arranged along a fourth spiral line, the fourth spiral linehaving a fourth origin, at least three fifth recesses arranged along afifth spiral line, the fifth spiral line having a fifth origin, at leastthree sixth recesses arranged along a sixth spiral line, the sixthspiral line having a sixth origin, and at least three seventh recessesarranged along a seventh spiral line, the seventh spiral line having aseventh origin, wherein each of the first origin, third origin, fourthorigin, fifth origin, sixth origin, and seventh origin are located on anelliptic ring, the elliptic ring having a second center point which isoffset from the first center point; and a grinding plate operablyconnected to the grinding wheel and including: at least three eighthrecesses arranged along an eighth spiral line, and at least three ninthrecesses arranged along a ninth spiral line, wherein the eighth spiralline intersects the ninth spiral line in a region of at least one recessof the at least three eighth recesses and the at least three ninthrecesses.
 22. The system of claim 21, wherein the second origin isoffset from the center point of the grinding wheel.
 23. The system ofclaim 22, wherein: each of the eighth recesses is aligned with arespective one of the first recesses; and each of the ninth recesses isaligned with a respective one of the second recesses.
 24. The system ofclaim 21, wherein: each of the eighth recesses is aligned with arespective one of the first recesses; and each of the ninth recesses isaligned with a respective one of the second recesses.
 25. A structuralunit having a hole pattern for sucking away swarf from a machiningsurface comprising: at least three first recesses arranged along a firstspiral line, the first spiral line having a first origin; at least threesecond recesses arranged along a second spiral line, the second spiralline having a second origin, wherein the second spiral line intersectsthe first spiral line in a region of at least one recess of the at leastthree first recesses and the at least three second recesses; and atleast three third recesses arranged along a third spiral line, the thirdspiral line having a third origin, wherein the origin of the thirdspiral line is located closer to a center point of the structural unitthan the origin of the first spiral line.
 26. The structural unitaccording to claim 25, wherein the at least three first recesses arearranged at intersection points of the first and second spiral lines.27. The structural unit according to claim 25, wherein the first andsecond spiral lines are contradirectional to one another.
 28. Thestructural unit according to claim 27, wherein the first and secondcontradirectional spiral lines have different numbers of recesses. 29.The structural unit according to claim 27, wherein: the first spiralline is one of a first plurality of spiral lines; the second spiral lineis one of a second plurality of spiral lines; each of the firstplurality of spiral lines is contradirectional to each of the secondplurality of spiral lines; each of the first plurality of spiral linesis associated with a respective at least three first recesses; each ofthe second plurality of spiral lines is associated with a respective atleast three second recesses; a first total number of the first pluralityof spiral lines of the structural unit corresponds to a first Fibonaccinumber of a Fibonacci sequence; a second total number of the secondplurality of spiral lines correspond to a second Fibonacci number of theFibonacci sequence; and the first Fibonacci number is adjacent to thesecond Fibonacci number in the Fibonacci sequence.